Continuous-heating furnace



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J. F. FERM CONTINUOUS HEAT I NG FURNAC E Filed May 2( 192:5 2 sugars-sneer .2l

WFA/6565 JOHN F. FEBM, 0F IPITTSB'UH, PENNSYLVANIA.

CONTINUOUS-HEATING- FURNACE. I

Application lcd May 2', 1923. Serial 110.6361956.

To all 'wlwm it may concern Be it known that l, JOHN F.` FERM, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and the State of Pennsylvania, have Ina-de a new and useful Invention in Continuous-Heating Furnaces, of which the following is a specification.

My invention relates to a continuous heating 'furnace for heating ingots, blooms, slabs, or billets prior to rolling or forging.

An object of my invention is to construct a multiple hearth furnace having any desired capacity and which occupies no more floor space than is necessary for a single hearth furnace of the old type. Another object is to provide a multiple hearth furnace of any' desired capacity, which will `require less labor than the number of furnaces of the old type required for alike ca acity, and to decrease the fuel necessary y decreasing the 'radiating surface and at the same time to decrease the first cost of installation.

My inyention is shown as a double hearth furnace of either the side door or the end door discharge type in the drawings, in which, Figure 1 1s a longitudinal horizontal section of a furnace on theline 1-1 of Fig. 2 looking in the direction of the arrows. Fig. 2 is a longitudinal vertical section through the furnace on the line 2-2 of Fig. l looking in the direction of the arrows, and Fig. 3 is a vertical cross section on the line 3-3 of Fig. 2 looking in the direction of the arrows. Fig. 4 is a view similar to Fig. l showin the invention applied to an 'end door discharge continuous furnace taken on the line lt-4, of Fig. 5. Fig. 5 is a Vertical section on the line 5 5 of Fig. 4 looking in the direction of the arrows. f

Describin first a double hearth furnace of the lside oor discharge type as is shown in Figs. 1 to 3, the furnace comprises a lower hearth l having water cooled skids 1a which corresponds to the usual hearth in a single hearth furnace. Formed by a continuation of this hearth 1 is the uncooled finishing hearth 2 adjacent to which is the discharge door 3. Above the lower hearths 1 and 2 are skids 4 supported on water cooled pipes 5 forming an upper or second preheating hearth. The `water cooled supports 5 for the upper hearth may be covered with a refractory insulation to prevent heat loss, if

p desired. At the entrance end of the preheating hearths are provided the charging doors 6 outside of which are the skids 7 and 8 where the cold stock isplaced for charging the preheating hearths 4 and 1 respectively. A double ram pusher 9 is provided for shoving cold stock into the furnace.

Two or more charging rams 12 are proyided for each hearth. Each char ing ram 1s` independently operable so that i there is more than one row of material on a preheatlng hearth each row canhbe independently advanced.

At the opposite end of the furnace from the charging doors and adjacent the'upper preheating hearth arev provided inclined skids 10 which are set in the brick work and are for the purpose of directing the preheated material such as billets or ingotsfrom the upper hearth to the nishing hearthlatter are also connected to the air header The fan or blower 15 draws air through a preheating. chamber 20 i which is formed above the furnace roof by an upper` metallic roof 21 which` may be'covered with sand and forms the top of the preheating chamber. In this manner the air supplied to the combustion ports is preheated by radiation from thehottest part of the furnace.

1 rovide the usual peep holes 22 which -enab e the operator to inspect theinaterial during the heating thereof.

Turning now to the application of my. invention to a furnace of the end door discharge type which is illustrated in Figs. 41

`and 5 1 provide the same lower hearth 1 with the adjacent finishing hearth 2. The 105 ite.

door 29 leading to incline skids 30 down which the hot billets etc. slide to the roller table from the lower hearth.

In this furnace the air fan 15 forces the air through the connecting pipe 16 to the air header 14 for the combustion ports 11 for the upper hearth and through the connecting pipes 31 to a second air header32 which is connected by an air supply pipe 33to the lower combustion ports 17.

Describing first 'the operation of the furnace, illustra-ted in Figs. 1 to 3, and assuming that both hearths are filled with one or two rows of billets or slabs, depending upon their length, and also, assuming that a cold ,slab has been placed on the skids 7 and 8 in front of the pusher rams 9, the o erator as soon as a'hot slab or billet is ischarged from the finishing hearth 2 through the discharge door 3 by means of an ordinary pinch roller as is usual, inspects the upper and lower hearths and then has the rams 9 opposite the hearth with the hottest material racked forward. If the hot-test material is on the lower hearth the billets on the lower hearth are moved forward by the' rams and the billet nearest the discharge door is movedto a point on the finishing or uncooled hearth which was previously occupied by the billet just discharged from rthe furnace. If the hottest material is on the upper hearth the billets on this hearth are moved forward by the rams and the first billet on the hearth drops from the end of the skids 4 onto the inclined skids 10 and slides down these to the uncooled finishing hearth in front of the discharge door where it remains until discharged from the furnace and where the black spots or unheated portions caused by the water` cooled skids are removed. As soon as a billet is discharged from the furnace the operation is repeated.

In the case of the end door discharge furnace, illustrated in Figs. 4 and 5, each preheating hearth has a separate non-cooled section forming separate finishing hearths.

. The operation of this furnace is the same as that of the side door discharge f urnaceexcept that billets from .the yupper preheating hearth 4, instead of dropping down on to the lower finishing hearth 2, are forced on to the separate upper finishing hearth 25 and from there pass through the discharge door 26 on to the inclined skids 27 Adown which they slide to the roller table. Thebillets on the lower finishing hearth 2, when the black spots have been removed, are forced through the discharge door 29 and down the inclined skids 30 to the roller table.

In both types of furnaces, the upper hearth being made of skids, the exposed surface of the billets is increased and an even temperature isA maintained by radiation from the hotter hearth. The products of combustion sweep along the billets or hearths and finally at the charging end of the furnace pass down the common flue 23 leading to the stack.

The furnaces illustrated are shown as equipped for gas firing but I desire it to be understood that my invention is equally applicable to furnaces using other fuel such, for example, as oil, tar or powdered coal.

Having thus described my invention what I claim as new is y 1. A continuous heating furnace havin@ a plurality of hearths, a charging opening for each hearth, discharge openings for each hearth, independent combustion ports for each hearth and a common flue for the products of combustion.

2. A continuous heating furnace having plurality of super-imposed hearths and independent combustion ports for each hearth.

3. A continuous heating furnace having a plurality of super-imposed hearths, an independent combustion port for each hearth and a common flue.

4. A continuous heating furnace having a plurality of super-imposed hearths, a charging opening for each hearth, a discharging opening for each hearth, independent comitiustion ports for each hearth and a common y 5. A continuous heating furnace having two super-imposed hearths, independent combustion ports for each hearth and a common iue for productsof combustion.

i 6. A continuous heat-ing furnace having two super-imposed preheating hearths, a finishing hearth adjacent one of the preheating hearths for receiving material therefrom and means for directlng material from the other preheating hearth on to said finishing hearth.

7. A continuous heating furnace having two super-imposed preheating hearths, a finishing hearth adjacent the lower preheating hearth for receiving material therefrom and means for directing material from the upper preheating hearth downwardly on to said finishing hearth.

8. A continuous heating furnace having two super-imposedV preheating hearths, a finishing hearth adjacent to the lower preheating hearth for receiving material di rectl therefrom and skids for directing inateria from said upper hearth downwardly on to said finishing hearth.

9. A continuous heating furnace having a cooled up er hearth, a lower hearth having cooled and uncooled sections said uncooled section constituting a finishing hearth for receiving material from said cooled section and4 from said upper hearth.

10. A continuous heating furnace having lli attacca directing material from said upper hearthdownwardly on to said finishing hearth.

12. A continuous heating furnace having an upper hearth composed of skids supported on water cooled pipes, a lower hearth includin a section having water cooled skids an an uncooled section, said uncooled section constituting a nishing hearth for receiving material from the said cooled section andv from said upper hearth, skids for directing material from said upper hearth downwardly on to said finishing hearth, charging openings for each of said cooled hearths and a discharge opening for said finishing hearth.v

13. A continuous heating furnace having a cooled upper hearth, a lower hearth having 'cooled and uncooled sections, said uncooled section constituting a finishing hearth for receiving material from rsaid cooled section and from said upperhearth, fuel ports for said upper hearth, fuel ports for said lower hearth and a common flue for the products of combustion.

14. A continuous heatingjfurnace having a cooled upper hearth, a lower hearth having cooled and uncooled sections, said uncooled' section constituting a finishing hearth for receiving material from said cooled section and from said upper hearth, fuel ports for said upper hearth, fuel ports for said lower hearth, a common due for the products-of combustion and means for directing material from said upper hearth downwardly on to said finishinghearth.

15. A continuus heating furnace having a cooled upper hearth, a lower hearth having cooled and uncooled sections, said uncooled section constituting a finishing hearth for receiving material; from said cooled lsection and from said u per hearth, fuel ports for said upper heart fuell orts forsaid lower hearth, a common flue or the products of combustion and skids for directing material from said upper hearth downwardly on to said finishing hearth.`

16. A continuous heating 'furnace having a cooled upperhearth, a lower hearth having cooled anduncooled sec-tions, said uncooled section constituting a finishing hearth* for receiving material from said cooled section and from said upper hearth, fuel ports for said upperhearth, fuel for said lower hearth, a common Hue-for the products of combustion, skids for directing material from said upper hearth downwardly on to said nishing hearth and an air preheating chamber ahove said upp'er hearth and communicating with said fuel ports.

17. yA continuous heating furnace having a cooled upper hearth composed of skids supported on water cooled pipes, a lower hearth including a section having water cooled skids and uncooled sections, said uncooled section constituting a finishing hearth for receiving material from said cooled section and from said upper hearth,skids for directing material from said upperhearth ,downwardly on to said nishing hearth,`

combustion ports for said upper hearth, combust1on ports for said lower hearth, a

common ue for the products of combustion,

an air preheating chamber above said upper hearth and communicating with said fuel ports, chargingopenings for each of said cooled hearths adjacent said flue and a discharging opening for said finishing hearth.

18. A continuous heating furnace having a plurality f preheating hearths, a separate finishing hearth adjacent each preheating hearth, charging -o enings foreach preheating hearth and a discharge opening for each finishing hearth leading to a common exit.

19. A continuous' heating furnace having a .plurality A' of su er-imposed reheating hearths and a finishing hearth adjacenteach preheating hearth.

20. A continuous heating furnace having a plurality of super-imposed preheatingA hearths, a finishing hearth adjacent eacli` preheating/hearth, charging openings for each preheating hearth and a discharge opening for each finishing hearth leading to a common exit;

` 21. A continuous heating furnace having an upper watercooled preheating hearth, an

uncooled Ifinishing hearth adjacent thereto, a lower water cooled preheating hearth and -an uncooled finishing hearth adjacent thereto.l v

22. A continuous heating furnace having dit' llt)

an upper water cooled preheating hearth, an uncooled finishing hearth adjacent thereto,

a lower water cooled preheating hearth, an uncooled finishing hearth adjacent thereto, a charging openin for each preheating hearth a single disc arge exit leading from the furnace and a discharge opening leading from each finishing hearth to said exit.

23.'A continuous heating furnace having an upper water cooled preheating hearth, anuncooled finishing hearth adjacent thereto, a lower water cooled preheating hearth` a'lower uncooled finishing hearth adjacent thereto, fuel ports for said upper hearths, fuel ports for said lower hearths iat and a common iiue for the products of combustion.

` 24. A continuous heating furnace having an upper water'cooled preheating hearth, an uncooled finishing hearth adjacent thereto, a lower water cooled p-reheating hearth, a lower uncooled finishing hearth adjacent thereto, fuel ports for said upper hearth, fuel ports for said lower hearth, a common flue for the products of combustion and an air preheating chamber above said upper hearth and communicating with said fue] ports. A

25. A continuous heating furnace having two super-imposed preheatlng hearths comprising water lcooled skids, an upper and lower uncooled finishing hearths, combustion v ports for said upper hearths, combustion vb'ustion, charging openings for said preheatv ports for said lower hearths, an air preheating chamber above said upper hearth and communicating with said fuel ports and a common flue for the products of coming hearths adjacent said flue and dis charging openings for each finishing hearth leadin to a common exit.

26. continuous heating furnace having a plurality of preheating hearths, a inishing hearth adjacent each preheating hearth,`

preheating exit.

In testimony whereof, I have hereunto subscribed my name this 26th day of April, 1923. l

JOHN F. FERM. 

